It is known (Donnet J.-B., Bansal R. C., Wang M. J. (ed.), Gersbacher M: Carbon Black, Marcel Dekker Inc., New York, (1993), ed. 2, p. 386) that the structure of the carbon black has a considerable effect on the reinforcement behavior of carbon black in rubber mixtures, given that there is good adhesion of the polymer to the carbon black. Another well-known fact is that as specific surface area rises there is an increase in hysteresis and therefore in energy dissipation under periodic stress-and-strain conditions. Abrasion resistance increases as specific surface area rises. Impression set increases as specific surface area increases, and this is particularly disadvantageous for gaskets, since there is an attendant reduction in the pressure exerted by the gasket. For this reason, low-surface-area carbon blacks are used in particular for technical rubber products for which abrasion resistance is not of particular importance. These carbon blacks can also be used in the region of the tire substructure. The relatively low specific surface area of the carbon blacks thus leads to lowering of hysteresis and thus also to reduced rolling resistance. As mentioned previously, structure has a decisive effect on reinforcement. An increase in rolling resistance, caused by the tire substructure, results in higher fuel consumption and thus higher carbon dioxide emission. This is undesirable for economic and environmental reasons.
It is also known (Donnet, Bansal, Wang (ed.), Funt J. M., Sifleet W. L., Tommé M.: Carbon Black, Marcel Dekker Inc., New York, (1993), ed. 2, p. 390) that good dispersion of the carbon black within the polymer is achieved if the structure (COAN, OAN) has sufficient magnitude.
For economic and environmental reasons it is therefore desirable to use a low specific surface area in order to lower the rolling resistance of the tire substructure. It would moreover be desirable to lower the weight of the component, by using improved reinforcing effect to reduce filler content and thus component density. For economic and process-technology reasons it would be desirable to use an improved reinforcing effect of the filler to permit replacement of polymer content by oil in the rubber formulation. Another factor essential to the effectiveness of the filler is the extent of dispersion, and it is therefore desirable to use a filler that is easy to disperse.
US 2008/0110552 A1 discloses a carbon black with COAN greater than 90 ml/(100 g) and smaller than 150 ml/(100 g), and with BET greater than 50 m2/g and smaller than 69 m2/g. The distribution index DI, which is the ratio of Dw to Dmode, is greater than 1.15.
These carbon blacks lead to a non-ideal hysteresis level in the rubber mixture, because specific surface area is still high.
US 2003/0013797 A1 discloses a carbon black with STSA of from 10 to 200 m2/g, iodine number of from 15 to 250 mg/g, tint value of up to 130%, DBPA of from 20 to 450 ml/(100 g), CDBP of from 20 to 400 ml/(100 g), an iodine number:STSA ratio of from 0.4 to 2.5, an average particle size of from 14 to 250 nm, and less than 1% content of volatile constituents, in a polymer conductivity application.
US 005736992 A moreover discloses furnace blacks featuring specific STAB surface area of from 45 to 55 m2/g, specific iodine number of from 48-58 mg/g, tint value of from 65 to 75%, CDBP of from 90 to 100 ml/(100 g), and DBP of from 122 to 132 ml/(100 g). Said carbon black is produced via radial and axial addition of the oil within the zone of restricted cross section of the furnace black reactor.
Disadvantages of these carbon blacks are the low OAN level and the small difference between OAN and COAN. The specific surface area of this carbon black is moreover still high, with the attendant disadvantages.
JP11-302557 A moreover discloses a carbon black which has STAB surface area of: from 25 to 60 m2/g and DBP/(ml/100 g)>0.6*CTAB/(m2/g) 4-120. A Stokes diameter complying withDst/nm<6000 m2/g/CTAB+60is moreover demanded for the mode. A result of this situation is that the carbon blacks produced in JP11-302557 A comprise relatively small aggregates.
These lead to a non-ideal property profile for the carbon blacks.
JP07-268148 discloses a carbon black which has DBP greater than 140 ml/(100 g). The particle size is stated as dp=38 nm or 42 nm.
JP04-18438 discloses a carbon black with STSA<60 m2/g and DBP≦100 ml/(100 g).
JP01-272645 preferably uses a carbon black with an iodine number of from 10 to 40 ml/g and with DBP of from 100 to 500 ml/(100 g).
EP 1783178 discloses a furnace-black process in which a feedstock used for the carbon black is introduced in a first stage and is combined with a stream of hot gases, in order to form a precursor, consisting essentially of a carbon black in a reaction stream, and further amounts of the feedstock material used for the carbon black are then introduced to said precursor, with the aim of thus partially quenching the reaction stream and subsequently completely quenching the entire reaction stream. The stream of hot gases can be produced in the form of combustion gas from the reaction of a fuel with an oxidant, such as air, and the ratio of air to fuel here can vary from 1:1 (stoichiometric) up to an infinite ratio.